Upholstery support

ABSTRACT

The invention relates to an upholstery support for a seat, especially for utilization in an automobile. According to the invention, an especially lightweight of vehicle seat construction is achieved in that the upholstery support is built in the form of a sandwich. Essential elements in said sandwich-type construction are a shell mold allocated to a soft upholstery and a back wall element. A shaped foam part, preferably made of hard foam, is inserted between the latter.

The invention relates to an upholstery support for a seat or a seatingbench, especially for use in a vehicle.

An upholstery support such as this is known, for example, from DE 195 41999-A1 (B64D11/06). The latter describes an upholstery support designedas a seat component, one which is in the form of a shell and may consistof plastic or sheet metal. The upholstery support described in thisreference is preferably a component of an aircraft passenger seat. Itmay be inferred from this reference that an especially lightconstruction may be obtained with the configuration described.

Another structure for a light-weight seat has been described in alecture, “Modern fiber materials and plastics on the vehicle seat”(Kmitta, Haus der Technik, Vehicle Seat Symposium of Sep. 27/28 1994,Event Number 30-735-56-4). FIG. 15 illustrates a so-called hybrid backrest in which use is made of a metal structural component absorbingstress and torque, a component joined to a real rigidifyinghigh-resistance foam. With respect to its construction the metalstructure shown there is comparable to that of a lightweight seat asdescribed on page 52 of Autozeitung [Automotive Journal] October 1997.The seat frame shown there is of more or less conventional design, and,in order to reduce weight, is made of a light metal, preferably diecastmagnesium.

U.S. Pat. No. 5,100,204 and U.S. Pat. No. 4,568,124 disclose upholsterysupports which are in tubular form for achievement of lightweightconstruction. U.S. Pat. No. 4,568,124 discloses use of the relativelyunstable construction in order to obtain specific pneumatic shockabsorption properties. U.S. Pat. No. 5,100,204 describes mounting ofexternal reinforcing elements on the upholstery support in order tostabilize it.

DE-9012858.3-U1 shows an upholstery support of single-layer design ontowhich is molded a pouch into which an absorbing element, preferably ofhigh-resistance foam, may be inserted to form a support for the lumbarvertebrae.

The object of the invention is development of additional means of weightreduction for upholstery supports of seats or seating benches.

This object is attained with an upholstery support if characterized bythe features described in claim 1. The dependent claims relate toespecially expedient developments of the invention.

It is claimed for the invention that the upholstery support is ofsandwich design, in which a shell mold receiving large-area padding onone side and a rear-wall element on the other enclose a molded foamelement between them. This molded foam element is preferably in the formof high-resistance foam with a so-called volume weight of 10 to 30 gramsper liter. The high-resistance foam element may be designed either as aninsert which is introduced between the shell mold and the rear-wallelement or is injected into the cavity formed by the shell mold and therear-wall element.

The fact that entirely conventional forming technology may be employedto produce the shell mold and the rear wall element made of light sheetmetal plates, for example, is a particular advantage of the upholsterysupport claimed for the invention. Similarly, a suitably shapedhigh-resistance foam block may be conventionally manufactured and theneither introduced between the sheet metal elements as a separatecomponent or cemented to at least one of the sheet metal elements.Joining of the sheet metal elements may be effected, for example, byadhesion and/or riveting and/or welding and/or folding.

In a preferred development of the invention the shell mold, for example,is partly perforated, especially in the area of a cavity receiving theelement introduced. As a result of this perforation, additional weightreduction is achieved, and also the moisture resulting from passengerperspiration can escape into the high-resistance foam block element. Anair conditioning function may thus also be assigned to the upholsterysupport claimed for the invention.

The sandwich structure here proposed results in extremely high strengthalong with very low structural weight, especially for the reason thatthe upholstery support as a whole, that is, optionally with theexception of the marginal areas, may be designed to have very thickwalls. Particular emphasis is to be placed on the fact that the spacerequirement for resilient foam for upholstering may be reduced bypreshaping the shell mold. Hence the structural volume may be put to adistinctly different use than in the case of conventional seatstructures. Application of the upholstery support claimed for theinvention results in a distinctly higher proportion of structural volumefor the upholstery support and a correspondingly substantially lowerproportion for the resilient foam upholstery without the need forsacrificing comfort.

Of particular importance for manufacture and installation of theupholstery supports claimed for the invention are high-resistance foamparts which are designed as aggregate vehicles. For example, foam may besimultaneously injected in advance into support elements for flexiblefoam upholstery, headrest guides, or supports for automatic seat beltwinders, and optionally metal stiffening elements. Thus, an aggregatesupport prepared in this manner may be positioned, completelypreassembled, between the shell mold and rear wall element to produceanother subassembly. The flexible foam upholstery may then be fastenedto suitably prepared mountings by simple clamps or conventional bracing.Fastening of the flexible foam upholstery by means of cementing is alsoconceivable.

The preferred application for the upholstery supports claimed for theinvention are back rests for the back seat benches of motor vehicles. Ofheightened importance in this context is the fact that, for example,cargo carried behind the back rest comes up against an upholsterysupport in the event of sudden vehicle deceleration. One the one handthis support is relatively rigid toward these stresses, and on the othermay be incorporated into the structure of the vehicle so as to absorbenergy in the case of use of injected-foam link pins. Consequently, nostructural changes in or additions to the body of a vehicle need be madeto reduce peak loads caused by collisions on impact with loose articlescarried in a vehicle. Hence what results in the aggregate is anupholstery support of high rigidity and simultaneously of greatductility. The overall structure of the support alone thus has a highenergy absorption potential.

An advantageous exemplary embodiment of the invention is illustrated inthe drawings, of which

FIG. 1 presents an exploded view of essential elements of an upholsterysupport as claimed for the invention,

FIG. 2 an upholstery support as a component of an upholstered back rest,

FIG. 3 a view of sectional plane III/III in FIG. 2,

FIG. 4 a molded foam element designed as unit support for the upholsterysupport claimed for the invention,

FIG. 5 preferred applications for upholstery supports as claimed for theinvention.

In all the figures the same reference numbers identify the samecomponents or sections of components.

Essential components of an upholstery support designated as 1 in FIG. 1are a shell mold 2, a shaped foam element 3, and a rear wall element 4.The latter has in this instance ribbing 5, which may optionally bedispensed with. If it is dispensed with, a simple flat metal sheet, forexample, may be used as rear wall element 4.

The outline of the shaped foam element 3 is fitted to rear wall element4 and the shell mold 2 and preferably is made of EPP or comparablehigh-resistance foam materials. In especially advantageous embodimentsthe volume weight of such materials ranges from 10 to 30 grams perliter. Particular note is to be taken that uniform distribution of thedensity or porosity of the foam over the entire structural volume ofmolded foam element 3 is not mandatory. For example, the foam strengthmay be lowered in a transitional area 6 between depressions 7 and 8.Specific heterogeneities in the shaped foam element 3 may be employed toensure that maximum strength and uniform workability are achieved with aminimum amount of foam materials.

The depressions 7′ and 8′ are in this instance provided with holepatterns 9 and 10 produced, for example, by punching or laser cutting.The area of a depression preferably ranges from 5 to 35 percent. Thediameters of the individual holes range, for example, from 20 to 50 mm.

Application of this measure results in saving of additional weight forthe shell mold 2. In addition, moisture resulting from perspiration canbe efficiently removed by means of a sieve structure in contact with thebody of a passenger. In addition, holes may also be provided outside thedepression in areas subjected to light loads. Directions of main forceflow, in contrast, remain devoid of holes. Holes may also be provided inthe rear wall element 4.

Preferably aluminum sheets of a thickness of 0.5 to 1.5 mm are used asbase material for the rear wall element 4 and the shell mold 2. Thethickness of the molded foam component 3 ranges in the center of thedepressions 7 and 8 preferably from 20 to 40 mm and from 80 to 100 mm onthe edges of the depressions, thus, for example in transitional area 6.

It is to be seen from the diagram in FIG. 1 that the upholstery supportis in this instance more or less square in shape. However, as claimedfor the invention, upholstery supports are not secured in position onthis shape. Consequently, more than two adjacent depressions may beprovided for buses, for example, and in addition the depressions on theedges may be positioned so that the shape of a U when viewed from aboveis obtained for the molded foam element 3, for example. Similarly, theupholstery supports for back rests may be designed as corner elementsfor camping vehicles or railroad cars.

FIGS. 2 and 3 show the upholstery supports 1 claimed for the inventiontogether with flexible foam padding 11 covered by a textile cover 12 andtogether with it secured to the upholstery support 1 by conventionalfastening elements 13 (for the sake of clarity only one of them is shownhere). In the embodiment shown in FIG. 3 the shell mold 2 is fastened tothe rear wall element 4 by a wraparound fold 14. As an alternative oraddition, however, connections by means of adhesion, welding, riveting,clinching, or the like may be provided. Also conceivable is expansion ofcupshaped semifinished material reshaped by interior high-pressurereworking into a one-piece hollow body which then has the shapeillustrated in FIG. 3. Analogously the geometry desired for a hollowbody of plastic, for example, may be produced by blow molding such as isknown in the manufacture of fuel tanks, for example.

The sketch presented in FIG. 2 shows clearly that no enlargements of anykind relative to conventional concepts are to be expected with respectto the structural volume for seats with upholstery supports 1 producedin accordance with the invention, so that the degree of comfort inpassenger compartments of small vehicles in particular is not negativelyaffected. In addition, the configuration of the design is subject to norestrictions whatever.

The shaped foam element 3′ shown in FIG. 4, in this instance designed asa so-called aggregate support, is of great importance. Designated asaggregates here are functional elements, which on the one hand areprovided for fastening or mounting accessories such as safety belts andhead restraints and on the other perform the function of fixing theupholstery support 1 in the vehicle's body. In addition, fasteningelements for immobilizing upholstery elements such as clamps and buttonsare counted among such functional elements. Indicated diagrammaticallyin FIG. 4, for example, are vertical rows of press fasteners 15 to 17and a horizontal row of press fasteners 18 by which flexible foamcushions outfitted with corresponding counterparts (not shown here) arerestrained. In addition, foam-filled head restraint guides 19 and 20 areprovided which, if more or less the same in construction, may be takenfrom conventional seat mounts. Also shown here is an automatic beltwinding element which is mounted on an anchor plate injected into moldedfoam element 3′. Analogously, dual roller systems for integrated childseats, for example, such as those disclosed in DE195 37 169 (B60N2/26),may also be introduced. Coupling of an upholstery support designed withthe molded foam element 3′ to the vehicle body is effected in a lowerarea by means of drag bearing elements 22, 23, and in the area of theupper edge of the rests by way of set pins 24, 25. Lashings to the bodystructure may also be made, however, by way of rigid or adjustablefittings such as those of front-seat arm structures. Back rest locks maythen be dispensed with.

All functional elements may be inserted into a tool mold as an aggregatecomponent volume and directly enveloped in foam. Hence other assembly ormounting and fastening processes may then be completely dispensed with.Also of importance in this context is that no noteworthy changes have tobe made in the shell mold 2 and in the rear wall element 4. Openings forthe functional elements shown in FIG. 4 can be provided by simpleperforations.

Application of the upholstery supports claimed for the invention is notrestricted to use of back rests as illustrated in FIGS. 1 to 4.Embodiments in the form of divided back rests 26 or use of upholsterysupports as claimed for the invention in the gluteal area 27 of avehicle seat 28, an example of which is illustrated in FIG. 5, are alsoconceivable. As with the other drawings, functionally identicalcomponents are identified by the same numbers, to which prime marks (′)are added.

What is claimed is:
 1. An upholstery support for a seat or a seatingbench in a vehicle comprising a sandwich structure having a rigid shellmold associated with soft padding and a rigid rear wall elementadjoining said rigid shell forming a hollow body therebetween andenclosing at least one molded foam element.
 2. An upholstery support asdescribed in claim 1, wherein the shell mold is a molded body made oflight metal or plastic.
 3. An upholstery support as described in claim1, wherein the rear wall element is a molded body made of light metal orplastic.
 4. An upholstery support as described in claim 1, wherein themolded foam element is designed as an inserted element made ofhigh-resistance foam whose surfaces are shaped so as to conform to theshape of the rear wall element and the shell mold.
 5. An upholsterysupport as described in claim 1, wherein the molded foam element isproduced by injection into the hollow body.
 6. An upholstery support asdescribed in claim 5, wherein the hollow body is produced by blowmolding or internal high-pressure forming.
 7. An upholstery support asdescribed in claim 1, wherein the shape of the shell mold is modified toreceive gluteal padding.
 8. An upholstery support as described in claim1, wherein the shape of the shell mold is modified to receive back restpadding.
 9. An upholstery support as described in claim 4 or 5, whereinthe shell mold and rear wall element are shaped elements produced fromsheet metal which are connected by jointing techniques.
 10. Anupholstery support as described in claim 9, wherein the shell mold, therear wall element and the molded foam element are in the form ofaggregate supports onto which components are fastened.
 11. An upholsterysupport as described in claim 1, wherein the shell mold and the rearwall element have a pattern of holes.
 12. An upholstery support asdescribed in claim 1, wherein one of the shell mold and the rear wallelement have a pattern of holes.
 13. An upholstery support as describedin claim 10, wherein the components are selected from the groupconsisting of a head rest support, a head rest guide, a belt windingdevice, a belt lock, a link lock, a link pin, a padding fasteningelement and a bearing element.
 14. An upholstery support as described inclaim 1, wherein the molded foam element is designed as an insertedelement made of high-resistance foam whose surfaces are shaped so as toconform to the shape of one of the rear wall element and the shell mold.15. An upholstery support as described in claim 9, wherein the metal isaluminum.